Ability to restore in order of has_snapshot_children to assist restore with foreign key constraints

[westonganger]

Alternative to #33 to allow to work with foreign key constraints

Adds an option to Snaphot#restore!(order_by_definition: true) which will attempts to dynamically set the restore order of the records according to the current has_snaphot_children definition.

At this point not going to merge this just going to leave it here if someone needs the code.

Pros of this approach:

• Restore order can be changed with the application code (#33 cannot solve this problem)

Cons of this approach

• Cannot determine restore order for polymorphic associations (#33 solves this issue)

[westonganger]

Closing as this is just for example. This gem will not support foreign key constraints it adds too much complication.